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// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import 'dart:async';
import 'package:flutter/material.dart';
import 'package:flutter/scheduler.dart';
import 'package:flutter/services.dart';
import 'package:flutter_driver/driver_extension.dart';
void main() {
enableFlutterDriverExtension();
debugPrint('Application starting...');
runApp(const MyApp());
}
class MyApp extends StatefulWidget {
const MyApp({super.key});
@override
State createState() => MyAppState();
}
const MethodChannel channel = MethodChannel('texture');
enum FrameState { initial, slow, afterSlow, fast, afterFast }
class MyAppState extends State<MyApp> with SingleTickerProviderStateMixin {
int _widgetBuilds = 0;
FrameState _state = FrameState.initial;
String _summary = '';
IconData? _icon;
double _flutterFrameRate = 0;
Future<void> _summarizeStats() async {
final double? framesProduced = await channel.invokeMethod('getProducedFrameRate');
final double? framesConsumed = await channel.invokeMethod('getConsumedFrameRate');
_summary = '''
Produced: ${framesProduced?.toStringAsFixed(1)}fps
Consumed: ${framesConsumed?.toStringAsFixed(1)}fps
Widget builds: $_widgetBuilds''';
}
Future<void> _nextState() async {
switch (_state) {
case FrameState.initial:
debugPrint('Starting .5x speed test...');
_widgetBuilds = 0;
_summary = 'Producing texture frames at .5x speed...';
_state = FrameState.slow;
_icon = Icons.stop;
channel.invokeMethod<void>('start', _flutterFrameRate ~/ 2);
case FrameState.slow:
debugPrint('Stopping .5x speed test...');
await channel.invokeMethod<void>('stop');
await _summarizeStats();
_icon = Icons.fast_forward;
_state = FrameState.afterSlow;
case FrameState.afterSlow:
debugPrint('Starting 2x speed test...');
_widgetBuilds = 0;
_summary = 'Producing texture frames at 2x speed...';
_state = FrameState.fast;
_icon = Icons.stop;
channel.invokeMethod<void>('start', (_flutterFrameRate * 2).toInt());
case FrameState.fast:
debugPrint('Stopping 2x speed test...');
await channel.invokeMethod<void>('stop');
await _summarizeStats();
_state = FrameState.afterFast;
_icon = Icons.replay;
case FrameState.afterFast:
debugPrint('Test complete.');
_summary = 'Press play to start again';
_state = FrameState.initial;
_icon = Icons.play_arrow;
}
setState(() {});
}
@override
void initState() {
super.initState();
_calibrate();
}
static const int calibrationTickCount = 600;
/// Measures Flutter's frame rate.
Future<void> _calibrate() async {
debugPrint('Awaiting calm (3 second pause)...');
await Future<void>.delayed(const Duration(milliseconds: 3000));
debugPrint('Calibrating...');
late DateTime startTime;
int tickCount = 0;
Ticker? ticker;
ticker = createTicker((Duration time) {
tickCount += 1;
if (tickCount == calibrationTickCount) { // about 10 seconds
final Duration elapsed = DateTime.now().difference(startTime);
ticker?.stop();
ticker?.dispose();
setState(() {
_flutterFrameRate = tickCount * 1000 / elapsed.inMilliseconds;
debugPrint('Calibrated: frame rate ${_flutterFrameRate.toStringAsFixed(1)}fps.');
_summary = '''
Flutter frame rate is ${_flutterFrameRate.toStringAsFixed(1)}fps.
Press play to produce texture frames.''';
_icon = Icons.play_arrow;
_state = FrameState.initial;
});
} else {
if ((tickCount % (calibrationTickCount ~/ 20)) == 0) {
debugPrint('Calibrating... ${(100.0 * tickCount / calibrationTickCount).floor()}%');
}
}
});
ticker.start();
startTime = DateTime.now();
setState(() {
_summary = 'Calibrating...';
_icon = null;
});
}
@override
Widget build(BuildContext context) {
_widgetBuilds += 1;
return MaterialApp(
home: Scaffold(
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
const SizedBox(
width: 300.0,
height: 200.0,
child: Texture(textureId: 0),
),
Container(
width: 300.0,
height: 60.0,
color: Colors.grey,
child: Center(
child: Text(
_summary,
key: const ValueKey<String>('summary'),
),
),
),
],
),
),
floatingActionButton: _icon == null ? null : FloatingActionButton(
key: const ValueKey<String>('fab'),
onPressed: _nextState,
child: Icon(_icon),
),
),
);
}
}